about a year ago engine light came on, dealer said all 4 o2 sensors were bad. autozone confirmed it. a year later i finally changed all 4 sensors. engine light was off, but then came back on later the next day. autozone pulled the codes and they said all 4 o2 sensors, they cleared the codes and all was good for a while then the light came on again. does it take a couple driving cycles for the new sensors to be recognized or is there another problem? thanks for any help.
about a year ago engine light came on, dealer said all 4 o2 sensors were bad. autozone confirmed it. a year later i finally changed all 4 sensors. engine light was off, but then came back on later the next day. autozone pulled the codes and they said all 4 o2 sensors, they cleared the codes and all was good for a while then the light came on again. does it take a couple driving cycles for the new sensors to be recognized or is there another problem? thanks for any help.
This may sound dumb but I kept getting a false faulty 02 sensor error code because my gas cap did not seal tight enough. 5 bucks for a new cap at PepBoys (stant) and no more light...at least for the last 5-6 months.
I think Autozone put one over on ya...there is no code in the OBD-II system to say "all four are bad". You'd literally have to have each individual code show (Sensor 1, Bank 1; Sensor 2, Bank 1; Sensor 1, Bank 2; Sensor 2, Bank 2) to conclude that they were ALL bad. Did Autozone or the dealership actually show you the scan tool, showing all four to be bad.
If that was actually the case...four individual codes for each sensor, something else has gotta be wrong...they just don't go bad all of a sudden...and certainly not all four at the same time. If the O2 sensor wiring was okay, I would suspect the computer. Or else, maybe it's a "phantom" code like CurryKid got, but I still wouldn't expect it to give ALL FOUR individual O2 sensor codes.
and it wasnt just autozone, the nissan dealer said all 4 were bad before autozone confirmed it. and yes i saw the code scanner and yes it came up with four different codes all pertaining to each o2 sensor.. the light came on a long time ago and we drove it like that for a while before we knew what was wrong, then by that time all four were bad.. they certainly looked toasted when i took them out. thanks for your input and help.
I had a similar problem issue with Nissan O2 sensors in my ’96 XE. My check engine light would come on during the ride home from NC. The ride is about 400 miles. I asked AutoZone to read the code(s). Bank 2, sensor 2 O2 fault.
I followed my factory service manual to confirm a bad O2 sensor but never found anything wrong with it. I used my OBD-II scanner to clear the code. My check engine light stayed off until my next return trip from NC. When I got home, I read the code, and found that once again the O2 sensor in bank 2, sensor 2 to be the culprit. This time, I ordered a nice new one from Nissan thinking that I would get something other than a Bosch O2 sensor. I did not; Nissan sold me a Bosch. I replaced it and cleared my code to turn off the check engine light.
Again all was fine until my return trip from NC. This time I searched the internet for an answer. I found an article about Nissan O2 sensors. The author stated that Nissan O2 sensors are sensitive to the Sulfur content in fuel. The author also quoted a study done in Canada where Exxon fuel was found to be higher in Sulfur content than the other leading fuel manufacturers. Interestingly enough, I would always stop at the same Exxon gas station in NC before I started my trip home. I no longer buy Exxon fuel, I still travel to NC on a very regular basis, and I have not had a problem with my O2 sensor.
Try buying gas at another gas station. It might just be the answer.
Sounds like you've got the problem listed in a TSB for multiple oxygen sensor trouble codes. The TSB is NTB99-004A and affects 96-99 pathfinders, here's the text:
This incident can be caused by poor grounding between the intake manifold and the engine cylinder head. The incident can be verified with a voltage drop check. The incident is corrected by the installation of a sub-harness between the intake manifold ground bolts for the engine harness and the right hand (RH) cylinder head to provide a direct grounding path.
Here's how you check if this is the problem:
Check for poor grounding using a DVOM to measure the voltage drop between the intake manifold ground bolt for the engine harness and the right hand (RH) cylinder head. At engine warm idle, place the red meter lead on the intake manifold ground bolt for the engine ECCS harness and the black lead on RH cylinder head and measure the voltage.
If the voltage is less than 0.020V (20 millivolts), this bulletin does not apply. Use the service manual to diagnose this incident.
Someone on the 4x4parts forum had multiple O2 sensor error codes and this was the cause, maybe you'll get lucky with this test. Post again if this test fails and I can send you the part#'s and repair steps from the TSB if you don't already have it.
i unhooked the battery overnight to try this, if the light comes back on during the drive to work i will try your test when i get home.. post the parts and instructions if you would anyway please, i dont have access to TSB info... thanks for your help. ill let you know what happens.
engine light was off until the next time i started it up.. i checked the voltage with an vhom and it was around .019, .020 or more... so i guess that qualifys me for the tsb problem with the ground. now i need the part number and info on were to get it.
or is it just supposed to take a while for the system to get used to the new sensors? i put in 4 brand new denso's to replace the factory bosch ones.
this is giving me a headache.
thanks again.
Last edited by bonecollector : Dec 12th, 2003 at 05:04 AM.
Here's the parts and steps, not sure how much it will help without the figures. I tried sending them to you via email but your profile doesn't allow emails. Send me an email and I can send you everything.
Parts
Harness - Engine Sub 24075-0W060 Qty1
Wiring - Clip 01552-00401KK Qty4
Bolt - Hex 08146-8121G Qty2
SERVICE PROCEDURE
1. Check for poor grounding using a DVOM to measure the voltage drop between the intake manifold ground bolt for the engine harness and the right hand (RH) cylinder head. At engine warm idle, place the red meter lead on the intake manifold ground bolt for the engine ECCS harness and the black lead on RH cylinder head and measure the voltage.
A. If the voltage is less than 0.020V (20 millivolts), this bulletin does not apply. Use the service manual to diagnose this incident.
B. If the voltage is above 0.020V (20 millivolts), install the sub-harness shown in Figure 1 for additional grounding. Continue with step two of this bulletin.
2. Route the sub-harness from the RH cylinder head, on the existing ECCS harness, towards the center front of the engine and then back towards the intake manifold collector (see Figure 2).
3. Secure the sub-harness end with the two larger eyelets to the two available threaded holes in the RH cylinder head adjacent to the negative battery cable attachment point (see Figure 3). Use the two new hex bolts listed in the parts information.
CAUTION: To prevent damage, the sub-harness must be positioned more than 70 mm (2.8 in.) from the exhaust manifold.
4. Secure the sub-harness to the ECCS harness at four (4) places (see Figure 4) using the wiring clips listed in the parts information. Note the spacing between the wiring clips shown in Figure 4.
5. Secure the sub-harness end with the two smaller eyelets to two of the existing ground bolts located on the intake manifold (see Figure 4).
6. Trim the excess material from the newly installed wiring clips.
1. Check for poor grounding using a DVOM to measure the voltage drop between the intake manifold ground bolt for the engine harness and the right hand (RH) cylinder head. At engine warm idle, place the red meter lead on the intake manifold ground bolt for the engine ECCS harness and the black lead on RH cylinder head and measure the voltage.
A. If the voltage is less than 0.020V (20 millivolts), this bulletin does not apply. Use the service manual to diagnose this incident.
B. If the voltage is above 0.020V (20 millivolts), install the sub-harness shown in Figure 1 for additional grounding. Continue with step two of this bulletin.
Shouldn’t we be checking the resistance between these two ground points?
okay, i guess i was too tired the first time i tested... so this time at warm idle it was showing a fluctuation between .019,.020,.021... so does that mean i dont have that problem?
Sorry, can't help any further since I haven't had the problem. You might try going to 4x4parts.com and PM 97inCali, he had the same problem and the TSB fixed it. Or search on that TSB number and you can find the posts for the problem. Good luck.
okay so i tried the tsb fix for the ground strap with no luck.. i went back to autozone to get the codes pulled and i wrote them down this time.. the OBD II Scanner showed P0135, P0151, P0155 and P0161. does anyone have any bright ideas, besides taking it to the dealer and paying out my arse to get it fixed? thanks again..
I sounds to me like the heater circuit(s) is/are not working. Without power to the heater element, the O2 sensor is probably not heating up quickly enough and the computer knows it. If this is the problem, simply installing new sensors will NOT solve the problem, because the sensors themselves are not faulty -- the circuit supplying power to the heating element is at fault. This means that one of the wires (the heating power wire) to one or multiple O2 sensors is dead...possible causes include a short, bad ground, or maybe even a bad PCM. Again, if the heater circuits are really at fault (further diagnosis is necessary), replacing the O2 sensors will not fix the problem.
If I diagnosed this at home, I'd probably start with figuring out which wire is the power wire (a factory service manual will be invaluable in this case -- available from Nissan electronically) and checking the voltage to that wire (unplug the sensor) while the engine runs. If one or more of the power wires has no voltage to it, I'd say you're starting to narrow in to your problem.
well those are the numbers the guy at autozone wrote down..
would it be alright to leave the new grounding sub harness on or should i remove it..?
i checked the voltage on all 4.. they had some voltage before engine was running and a little less when it was, any idea how much voltage they are supposed to have?
if i unplug the battery for a while and then start it the light doesnt come on, i can drive for miles and miles and it wont come on, but as soon as i turn it off and then start it back up the light comes on right away..
this problem is driving me nuts.. i am thinking i am gonna have to shell out the dough at the dealers.
Last edited by bonecollector : Jan 6th, 2004 at 12:10 AM.
Linear Mode
